Every single string in an XT set is treated with D'Addario's protective microcoating, a super-thin surface treatment that effectively repels dirt and sweat. XT strings last 4x longer than traditional uncoated strings without affecting the tone and feel of the game that D'Addario strings have been recognized for. D'Addario's unique steel ball core combined with a strong anchoring of the ball using so-called Fusion Twist technology provides a string with unparalleled strength and that holds its tuning significantly better than regular strings.
